Has this issue been resolved yet? I also reached out to the support team to get some assistance with my receipt forwarding feature not working either. Like the original poster, I had been using receipt forwarding up until I had changed and verified the email associated with my account, now ever since the forwarding feature no longer works.

Unfortunately the response from the Quickbooks team wasn't helpful at all, and no information was given to provide me with a solution, rather they closed my case. ( As seen below)

"Thank you for requesting updates on QBSE (US/CA) - Unable to forward receipts. After a, thorough evaluation our engineers have been unable to reproduce the report behavior. As a result, we’ve closed the current investigation. If new information surfaces we may re-open this investigation. We appreciate your understanding.

There will be no further updates on this issue."

It appears this has been an ongoing issue for years now and it's quite surprising that the internal team has not solved this yet.